I bought a D975XBX and it won't boot. Fans and LEDs come on for a few seconds each time I hit the soft "On" button and that's it. There is green LED lit up near the 2 X 12 power connector when the supply switch is on. After hitting the soft "on" button repeatedly the power will stay on, but no beeps and the screen remains blank. Here's what I have in the box. D975XBX with numbers on board... BQBX640000AW AA D25932-305. An Intel Pentium Extreme Edition 965, 3.73 GHz, T/LGA 775, 1066 FSB, 2X2MB L2 cache. The video board is an ASUS ENG8400GS Silent (does not have an extra power connector). The power supply is a Coolmax CXI-600B and has the 2x12 power connector. According the Intel manual, the 2x12 connector is the only power the board needs. It does not need the 1x4 connector (although I tried connecting this and the problem persisted). The manual also says "Do not use the 2x2 to 2x4 adapter when using an Intel® Pentium® processor Extreme Edition" which I am using so this connector is empty. Also, all the above items are new (although I am suspicious of the motherboard supplier since the static bag was previously opened, the I/O plate was not correct, and the motherboard CDROM was an office depot CD, not an original Intel CD.) I have measured the 12V, 5V, and 3.3V supplies with a multi-meter and they are all good. Any ideas??
You absolutely HAVE to plug in the 8-pin CPU power connector. That supplies power to the CPU. The system doesn't have a chance of booting without power to the CPU. What the motherboard owners manual was trying to say is to not use an adapter that takes a 4-pin CPU power connector and converts it into an 8-pin CPU power connector. You're kind of out of luck, though, since it doesn't look like your POS PSU even comes with an 8-pin CPU power plug. You should return that junk power supply for a good one. Make sure the new PSU has an 8-pin connector.
Here's a quality PSU that would easily power your system: